Pullups in detail 01 – Introduction
The best position to do this exercise would be standing since it would closely replicate how you would be on a bar pullup. However, this would require the band to be tied up very high, so using your knees might be the only option.
If you are using your knees, try to still engage your abs and squeeze your glutes to align your hips correctly. Essentially, we want to be as close to the bodyweight pull-up position as we can possibly be.
Scaling the difficulty up or down.
There are a few different ways (that I have used in the past) to adjust the difficulty of this exercise.
You can shorten or lengthen the band by wrapping it over the pull-up bar or the bar you are pulling on more or fewer times.
Changing the thickness of the band by using a different one.
Use multiple bands at the same time to increase the resistance.
A combination of all of the above.
Easier at the top, harder at the bottom.
Just because the way the band works, you will always find the beginning part of the pull easier than at the end, with a gradual increase.
This is not the exact way that a bodyweight pull-up works since that will be usually harder at the start and end, with the middle section being a little easier. The reason for this is because the middle section is the part your arms would have had the most use and will be at their strongest.
The accuracy of resistance.
If you wish to have a much more accurate reading of the amount of tension (and stress on your body) that the bands are giving you, then a simple hooked weighing scale can come in useful.
You can hook the scale onto the band and pull it down to the lowest point. Record the amount of weight that you are pulling as a way to gauge your progress.